RDMA/mlx: Calling qp event handler in workqueue context

Move the call of qp event handler from atomic to workqueue context,
so that the handler is able to block. This is needed by following
patches.

Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Reviewed-by: Patrisious Haddad <phaddad@nvidia.com>
Link: https://lore.kernel.org/r/0cd17b8331e445f03942f4bb28d447f24ac5669d.1672821186.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

1 files changed, 85 insertions, 36 deletions

diff --git a/drivers/infiniband/hw/mlx4/qp.c b/drivers/infiniband/hw/mlx4/qp.c
index b17d6ebc5b70..884825b2e5f7 100644
--- a/drivers/infiniband/hw/mlx4/qp.c
+++ b/drivers/infiniband/hw/mlx4/qp.c
@@ -102,6 +102,14 @@ enum mlx4_ib_source_type {
 	MLX4_IB_RWQ_SRC	= 1,
 };
 
+struct mlx4_ib_qp_event_work {
+	struct work_struct work;
+	struct mlx4_qp *qp;
+	enum mlx4_event type;
+};
+
+static struct workqueue_struct *mlx4_ib_qp_event_wq;
+
 static int is_tunnel_qp(struct mlx4_ib_dev *dev, struct mlx4_ib_qp *qp)
 {
 	if (!mlx4_is_master(dev->dev))
@@ -200,50 +208,77 @@ static void stamp_send_wqe(struct mlx4_ib_qp *qp, int n)
 	}
 }
 
+static void mlx4_ib_handle_qp_event(struct work_struct *_work)
+{
+	struct mlx4_ib_qp_event_work *qpe_work =
+		container_of(_work, struct mlx4_ib_qp_event_work, work);
+	struct ib_qp *ibqp = &to_mibqp(qpe_work->qp)->ibqp;
+	struct ib_event event = {};
+
+	event.device = ibqp->device;
+	event.element.qp = ibqp;
+
+	switch (qpe_work->type) {
+	case MLX4_EVENT_TYPE_PATH_MIG:
+		event.event = IB_EVENT_PATH_MIG;
+		break;
+	case MLX4_EVENT_TYPE_COMM_EST:
+		event.event = IB_EVENT_COMM_EST;
+		break;
+	case MLX4_EVENT_TYPE_SQ_DRAINED:
+		event.event = IB_EVENT_SQ_DRAINED;
+		break;
+	case MLX4_EVENT_TYPE_SRQ_QP_LAST_WQE:
+		event.event = IB_EVENT_QP_LAST_WQE_REACHED;
+		break;
+	case MLX4_EVENT_TYPE_WQ_CATAS_ERROR:
+		event.event = IB_EVENT_QP_FATAL;
+		break;
+	case MLX4_EVENT_TYPE_PATH_MIG_FAILED:
+		event.event = IB_EVENT_PATH_MIG_ERR;
+		break;
+	case MLX4_EVENT_TYPE_WQ_INVAL_REQ_ERROR:
+		event.event = IB_EVENT_QP_REQ_ERR;
+		break;
+	case MLX4_EVENT_TYPE_WQ_ACCESS_ERROR:
+		event.event = IB_EVENT_QP_ACCESS_ERR;
+		break;
+	default:
+		pr_warn("Unexpected event type %d on QP %06x\n",
+			qpe_work->type, qpe_work->qp->qpn);
+		goto out;
+	}
+
+	ibqp->event_handler(&event, ibqp->qp_context);
+
+out:
+	mlx4_put_qp(qpe_work->qp);
+	kfree(qpe_work);
+}
+
 static void mlx4_ib_qp_event(struct mlx4_qp *qp, enum mlx4_event type)
 {
-	struct ib_event event;
 	struct ib_qp *ibqp = &to_mibqp(qp)->ibqp;
+	struct mlx4_ib_qp_event_work *qpe_work;
 
 	if (type == MLX4_EVENT_TYPE_PATH_MIG)
 		to_mibqp(qp)->port = to_mibqp(qp)->alt_port;
 
-	if (ibqp->event_handler) {
-		event.device     = ibqp->device;
-		event.element.qp = ibqp;
-		switch (type) {
-		case MLX4_EVENT_TYPE_PATH_MIG:
-			event.event = IB_EVENT_PATH_MIG;
-			break;
-		case MLX4_EVENT_TYPE_COMM_EST:
-			event.event = IB_EVENT_COMM_EST;
-			break;
-		case MLX4_EVENT_TYPE_SQ_DRAINED:
-			event.event = IB_EVENT_SQ_DRAINED;
-			break;
-		case MLX4_EVENT_TYPE_SRQ_QP_LAST_WQE:
-			event.event = IB_EVENT_QP_LAST_WQE_REACHED;
-			break;
-		case MLX4_EVENT_TYPE_WQ_CATAS_ERROR:
-			event.event = IB_EVENT_QP_FATAL;
-			break;
-		case MLX4_EVENT_TYPE_PATH_MIG_FAILED:
-			event.event = IB_EVENT_PATH_MIG_ERR;
-			break;
-		case MLX4_EVENT_TYPE_WQ_INVAL_REQ_ERROR:
-			event.event = IB_EVENT_QP_REQ_ERR;
-			break;
-		case MLX4_EVENT_TYPE_WQ_ACCESS_ERROR:
-			event.event = IB_EVENT_QP_ACCESS_ERR;
-			break;
-		default:
-			pr_warn("Unexpected event type %d "
-			       "on QP %06x\n", type, qp->qpn);
-			return;
-		}
+	if (!ibqp->event_handler)
+		goto out_no_handler;
 
-		ibqp->event_handler(&event, ibqp->qp_context);
-	}
+	qpe_work = kzalloc(sizeof(*qpe_work), GFP_ATOMIC);
+	if (!qpe_work)
+		goto out_no_handler;
+
+	qpe_work->qp = qp;
+	qpe_work->type = type;
+	INIT_WORK(&qpe_work->work, mlx4_ib_handle_qp_event);
+	queue_work(mlx4_ib_qp_event_wq, &qpe_work->work);
+	return;
+
+out_no_handler:
+	mlx4_put_qp(qp);
 }
 
 static void mlx4_ib_wq_event(struct mlx4_qp *qp, enum mlx4_event type)
@@ -4468,3 +4503,17 @@ void mlx4_ib_drain_rq(struct ib_qp *qp)
 
 	handle_drain_completion(cq, &rdrain, dev);
 }
+
+int mlx4_ib_qp_event_init(void)
+{
+	mlx4_ib_qp_event_wq = alloc_ordered_workqueue("mlx4_ib_qp_event_wq", 0);
+	if (!mlx4_ib_qp_event_wq)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void mlx4_ib_qp_event_cleanup(void)
+{
+	destroy_workqueue(mlx4_ib_qp_event_wq);
+}